AIM 

4/20/23 

c. 

A minimum of 1.0 NM radar separation (diagonal) is required between successive aircraft on the adjacent 

final approach course when runway centerlines are at least 2,500 feet but no more than 3,600 feet apart. A 

minimum of 1.5 NM radar separation (diagonal) is required between successive aircraft on the adjacent final 

approach course when runway centerlines are more than 3,600 feet but no more than 8,300 feet apart. When 

runway centerlines are more than 8,300 feet but no more than 9,000 feet apart a minimum of 2 NM diagonal radar 

separation is provided. Aircraft on the same final approach course within 10 NM of the runway end are provided 

a minimum of 3 NM radar separation, reduced to 2.5 NM in certain circumstances. In addition, a minimum of 

1,000 feet vertical or a minimum of three miles radar separation is provided between aircraft during turn on to 

the parallel final approach course. 

d. 

Whenever parallel approaches are in use, pilots are informed by ATC or via the ATIS that approaches to 

both runways are in use. The charted IAP also notes which runways may be used simultaneously. In addition, 

the radar controller will have the interphone capability of communicating with the tower controller where 

separation responsibility has not been delegated to the tower. 

NOTE

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ATC will not specifically identify these operations as being dependent when advertised on the ATIS. 

EXAMPLE

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Simultaneous ILS Runway 19 right and ILS Runway 19 left in use. 

e. 

At certain airports, simultaneous dependent approaches are permitted to runways spaced less than 2,500 

feet apart. In this case, ATC will provide no less than the minimum authorized diagonal separation with the leader 

always arriving on the same runway. The trailing aircraft is permitted reduced diagonal separation, instead of 

the single runway separation normally utilized for runways spaced less than 2,500 feet apart. For wake turbulence 

mitigation reasons: 

1. 

Reduced diagonal spacing is only permitted when certain aircraft wake category pairings exist; typically 

when the leader is either in the large or small wake turbulence category, and 

2. 

All aircraft must descend on the glideslope from the altitude at which they were cleared for the approach 

during these operations. 
When reduced separation is authorized, the IAP briefing strip indicates that simultaneous operations require the 

use of vertical guidance and that the pilot should maintain last assigned altitude until intercepting the glideslope. 

No special pilot training is required to participate in these operations. 

NOTE

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Either simultaneous dependent approaches with reduced separation or SOIA PRM approaches may be conducted to 

Runways 28R and 28L at KSFO spaced 750 feet apart, depending on weather conditions and traffic volume. Pilots should 

use caution so as not to confuse these operations. Plan for SOIA procedures only when ATC assigns a PRM approach or 

the ATIS advertises PRM approaches are in use. KSFO is the only airport where both procedures are presently conducted. 

REFERENCE

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AIM, Para 5

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4

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16, Simultaneous Close Parallel PRM Approaches and Simultaneous Offset Instrument Approaches (SOIA). 

Arrival Procedures

5

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4

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